1. Technology Field
The disclosure generally relates to a power control method and a power control circuit, and more particularly, to a power control method and a power control circuit for a memory card with a smart card function.
2. Description of Related Art
Smart cards have been broadly used along with the widespread use of e-wallet and prepayment applications. A smart card is an integrated circuit (IC) card embedded with such components as a microprocessor, a card operating system, a security module, and a memory and which allows a card holder to perform various predetermined operations. Besides the function of data storage, a smart card also offers calculation, encryption, bidirectional communication, and security functions such that data stored in the smart card can be protected. A subscriber identification module (SIM) card used in a GSM (Global System for Mobile Communications) cellular phone is one of the many applications of smart cards. Generally speaking, a smart card has very limited storage capacity due to the specification of the IC therein.
Generally speaking, a user can access data in a memory card through a card reader. Thus, in an application wherein a smart card is integrated with a memory card, data stored in the memory card and the smart card can only be read through a card reader in a contact manner. However, along with the development of near field communication (NFC), many contactless sensing techniques have been broadly applied in our daily life, such as transit fare cards and access cards, etc.
Accordingly, a memory card combined with a smart card and a contactless access function such as a Micro Secure Digital (micro SD) memory card is developed. This kind of memory card receives different power inputs when being read by a reading apparatus within a host system under different conditions. Hence, if the smart card circuit inside the memory card can not work normally when any one of different power inputs is supplied, then the application range thereof will be significantly limited.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the disclosure. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the disclosure, or that any reference forms a part of the common general knowledge in the art.